May 20, 2005 - Cloned Embryos To Aid in Stem Cell Research

South Korean scientists have surmounted a key hurdle in stem cell research, reporting Thursday that they have produced 11 human embryo clones of injured or sick patients and harvested individualized stem cells -- a template for creating therapeutic cells for anyone.

The researchers collected 185 eggs from 18 healthy women and removed the genetic material from the nucleus. They then took skin samples -- about the size of a small button -- from 11 patients with spinal cord injuries, juvenile diabetes and a form of severe combined immunodeficiency disease, the so-called bubble boy disease.

The researchers took DNA from the skin samples and inserted it into the eggs.

The procedure resulted in 31 embryos. When they were five days old, the embryos were transferred to culture dishes, where 11 of them from nine patients developed into stem cells.

Tests verified that the stem cells were able to multiply as well as differentiate into neurons, muscle, bone, cartilage, respiratory and islet cells, among others.

The researchers were able to produce a cell line using an average of 16.8 eggs. In their previous paper, they required 242 eggs to create a single line of stem cells.

Recent advances in stem cell research are considered crucial to achieving the ultimate goal of customizing stem cells to treat individual patients, said Gerald Schatten, a biomedical researcher at the University of Pittsburgh and a coauthor of the study.

Researchers strongly suspect that tissues made from stem cells containing a patient's own genetic material are most likely to succeed in a transplant because there would be little danger of tissue rejection or other complications.

"This may be nature's best repair kit," said Schatten, who leads the Pittsburgh Development Center, a biology research institute.

Scientists, however, believe stem cells could be used to research other cures by illuminating "the cellular mechanisms that cause these diseases to occur," Fred H. Gage, a professor of genetics at the Salk Institute in La Jolla Gage said.

For instance, Gage envisions creating a line of stem cells using the DNA of a patient with pancreatic cancer.

"The embryonic stem cells don't have cancer, but they have the capacity for it," he said. "You could differentiate the cells into pancreatic cells and watch as the cancer develops."

Schatten said Hwang was also collaborating with researchers at Memorial Sloan-Kettering Cancer Center in New York who focused on degenerative diseases such as Parkinson's.

"This work is powerful evidence that stem cell research can unlock the keys to understanding and eventually treating conditions from spinal cord injuries to diabetes," said Daniel Perry, president of the Coalition for the Advancement of Medical Research.